The invention relates to centrifugation methods and apparatus, and more particularly to a novel and improved method and device for containing and applying a fixative agent or other treatment liquid to a specimen to be centrifuged.
Medical diagnostic processes commonly include collecting biological material specimens from patients for laboratory analysis. Biological materials subject to collection and analysis include, but are not limited to, blood, saliva, urine, epithelial smears, semen, and the like. Laboratory analysis of collected biological material frequently involves the use of a cytocentrifuge for separating fluid samples into various constituent components. A general description of the centrifugation process, and a suitable apparatus for accomplishing centrifugation of biological specimens, is contained in U.S. Pat. No. 4,705,630 to Hayes, assigned to the assignee of this invention, the disclosure of which is hereby incorporated by reference. Other background references providing details of cytocentrifuge construction and operation, and some of the advantages and disadvantages presented in the art, include U.S. Pat. No. 4,853,188 to Toya, No. 4,678,579 to Griffin, and No. 4,391,710 to Gordon, the respective disclosures of which also are incorporated by reference. Typically, the centrifuge is used to separate the specimen components, and force at least a portion of the specimen through a filter and onto a microscope slide for analysis.
After the specimen has been centrifuged onto the microscope slide, it often must be treated with chemicals, such, as fixative or preservative agents, dyes and the like. The current common practice is to place the specimen into the sample chamber and the chamber into the centrifuge, operate the centrifuge, and then remove the chamber from the centrifuge and/or open the chamber in order to access the specimen to apply the treatment liquid. This conventional manner of applying a treatment chemical to the specimen is time consuming and fraught with opportunity for sample contamination.
The present invention fills an unmet need for a simple, inexpensive, and convenient method and apparatus for applying a treatment liquid, such as a fixative agent, to a specimen immediately after centrifugation. While the present invention finds particularly beneficial use in cytocentrifuges for the analysis of biological materials specimens, one of ordinary skill in the art will readily appreciate that the invention has utility in the general art of centrifugation.